Document FR-2 065 734 discloses, in the embodiment of its FIG. 2, an aircraft undercarriage that includes a motor and gearing, both positioned to extend a hub of an undercarriage wheel, on the axis thereof. The motor serves to drive the wheel for self-propelled taxiing of the airplane on the ground without it being necessary to call on a tractor.
The gearing extends facing the rim of the wheel and beyond it in the axial direction. Unfortunately, that arrangement presents drawbacks. The gearing extending outside the volume of the undercarriage increases the overall size of the undercarriage. It is therefore necessary to provide a particularly large volume in the well in the airplane fuselage for receiving the undercarriage. However that reduces the performance of the aircraft and its capacity in terms of payload or passenger transport.
In addition, the gearing and the motor positioned in that way constitutes obstacles to dismantling the wheel or the brake, when that is necessary. Under such conditions, it is necessary to begin by dismantling the gearing and the motor in order to gain access to the wheel or the brake. Operations involving repairing or replacing the wheel or the brake are therefore lengthy and expensive.
Finally, when it is desired to cool the brake from the rim, the volume occupied by the gearbox once more constitutes an obstacle.